TWI848189B - Pants-type disposable diapers - Google Patents

Abstract

The problem to be solved by the present invention is to provide a trouser-type disposable diaper which suppresses the retraction of the end of the elastic stretch member and prevents the reduction of the adhesive force of the side seal. In order to solve this problem, the trouser-type disposable diaper of the present invention has an outer shell 20 forming a front body F and a back body B, and the two side parts of the outer shell 20 in the front body F are respectively joined with the two side parts of the outer shell 20 in the back body B to form a side seal 21, thereby forming a waist opening and a pair of left and right leg openings; in the front body F in the outer shell 20, the waist opening and the leg opening are formed. At least one of the back body B is bonded with a curved elastic member 26, 28 which is bent and extends from a side seal portion on one side to a side seal portion on the other side by means of an adhesive; the amount of the adhesive applied in an adjacent area adjacent to the inner side in the width direction of the aforementioned side seal portion 21 is greater than the amount of the adhesive applied on the outer side in the width direction of the aforementioned side seal portion 21.

Description

Pants-type disposable diapers

The present invention relates to a pants-type disposable diaper which suppresses the retraction of the end portion of a curved elastic member bonded to an outer body.

The pants-type disposable diaper comprises an outer body and an inner body, wherein the outer body has a front body and a back body, and the inner body is fixed to the inner surface of the outer body and contains an absorbent body, wherein the front body and the back body of the outer body are joined at both sides to form side seals, thereby forming a waist opening and a pair of left and right leg openings.

When the wearer of a pants-type disposable diaper urinates a large amount, the absorbent absorbs urine and the weight of the absorbent increases, so the crotch portion of the diaper sags downward. As a result, a gap is created between the wearer's skin and the diaper, which may cause urine leakage. In order to prevent the diaper from fitting poorly after urination, a curved elastic member is provided around the leg of the manufactured and sold diaper. The curved elastic member is used to pull up the crotch portion of the diaper to suppress urine leakage.

In the manufacturing process of diapers, there is a risk of applying adhesive directly to the flexible member itself. For example, the flexible member passes through a positioning guide, and the positioning guide moves back and forth in a direction perpendicular to the production line direction to make the flexible member curved. Therefore, when the adhesive is applied directly to the flexible member, there is a risk of the adhesive splashing on the production line when the positioning guide moves back and forth. Therefore, a hot melt bonding method is adopted, for example, in two cloth-like sheets that serve as the base material of the outer body, after applying an adhesive on the top surface of the lower sheet, a flexible member is placed on the applied adhesive, and then the upper sheet is covered on the flexible member, so that the flexible member is sandwiched between the upper and lower sheets, and the outer body in this state is pressed from top to bottom by rollers. After the flexible member is bonded between the two sheets in this way, the two cloth-like sheets are cut at a predetermined interval in the transverse direction (direction perpendicular to the direction of travel of the sheets), thereby completing the prototype of each diaper. When the sheet is cut, the elastic member is also cut. Generally, the diameter of the elastic member is small. As a result, the contact area between the elastic member and the lower sheet is small and the adhesion is not strong. Therefore, the end of the elastic member is easily pulled back to the inside of the width direction of the diaper and retracted. If the elastic member retracts, the contraction force is not easy to act on the end of the width direction of the diaper, so the fit of the diaper at the end of the width direction may be reduced.

In addition, as a related prior art document of the present invention, the following patent document 1 is cited. This patent document 1 discloses an absorbent article, which is provided with a leg elastic member for forming leg wrinkles in an extended state. The leg elastic member is cut at the crotch so that the elastic stretchability does not act on the portion where the absorbent body exists. Furthermore, the leg elastic member having the portion where the elastic stretchability does not act is fixed to the constituent material of the absorbent article by a second fixing means.

[Prior technical literature] (Patent literature) Patent literature 1: Japanese Patent Publication No. 2002-035030

[Problem to be solved by the invention] In order to solve the above-mentioned problem, a method is conceived, which is to apply different adhesives to the ends of the bending elastic member to improve the bonding strength of the bending elastic member. However, in general, because the ends of the bending elastic member are located in the side sealing part, when different adhesives are applied to the ends of the bending elastic member, it becomes necessary to increase the amount of adhesive applied in the side sealing part. The bonding of this side sealing part is mostly carried out by a bonding method different from the above-mentioned elastic expansion member, such as ultrasonic welding. At this time, if a large amount of adhesive is applied between the two sheets during ultrasonic welding, the ultrasound wave becomes difficult to transmit, and there is a problem that the bonding strength of the side seal is easily reduced. In addition, when ultrasonic welding is performed on the side seal, there is a tendency to improve the bonding strength of the side seal if there are no impurities between the upper and lower sheets. The adhesive of the bending elastic member is also included in the aforementioned impurities, so if the bonding strength of the side seal is to be improved, the amount of adhesive in the side seal must be as small as possible, which is a problem. If the amount of adhesive in the side seal is large, the adhesive is likely to seep out from the outer surface of the sheet at the side seal and may adhere to a conveyor belt or the like used to transport the sheet in the manufacturing device. Furthermore, if the amount of adhesive in the side seal is large, the softness of the portion of the sheet at the side seal is lost, so there is also a problem that the wearer's skin feels uncomfortable when it contacts the portion.

Therefore, the main problem to be solved by the present invention is to provide a pants-type disposable diaper which suppresses the retraction of the end portion of the elastic stretch member and prevents the reduction of the adhesive force of the side seal portion.

[Technical means for solving the problem] An aspect for solving this problem is as follows. ＜First aspect＞ A trouser-type disposable diaper, which has an outer shell forming a front body and a back body, and the two side portions of the outer shell in the front body and the two side portions of the outer shell in the back body are respectively joined to form side seals, thereby forming a waist opening and a pair of left and right leg openings; the trouser-type disposable diaper is characterized in that: The front body in the outer shell is At least one of the front body and the back body is bonded with a bending elastic member of the side seal portion that is bent and extends from the side seal portion of one side to the other side by an adhesive; the amount of the adhesive applied in the adjacent area adjacent to the inner side of the width direction of the side seal portion is greater than the amount of the adhesive applied on the outer side of the width direction of the side seal portion.

(Effect) The first aspect of the pants-type disposable diaper is characterized in that a larger amount of adhesive is applied in the adjacent area adjacent to the inner side in the width direction of the side seal. The end of the bending elastic member is located in the adjacent area, and the amount of adhesive applied in this adjacent area is increased, thereby making the bonding between the end of the bending elastic member and the outer body stronger than previous products. As a result, compared with previous products, it is possible to better suppress the end of the bending elastic member from being pulled back to the inner side in the width direction of the diaper and shrinking.

Furthermore, the first aspect of the pants-type disposable diaper is characterized in that the amount of adhesive applied to the outer side of the side seal in the width direction is small. As mentioned above, if the amount of adhesive applied to the outer side of the side seal in the width direction is large, there will be a problem of reduced adhesive strength of the side seal, so in this aspect, the amount of adhesive applied to the outer side of the side seal in the width direction is reduced to prevent the adhesive strength of the side seal from being reduced. At the same time, it is also possible to prevent the adhesive from leaking from the outer end of the side seal in the width direction. Furthermore, the adhesive can be prevented from leaking out onto the outer surface of the side seal portion and becoming hard, and the wearer can be prevented from coming into contact with the hardened portion and feeling uncomfortable.

<Second Aspect> The pants-type disposable diaper as described in the first aspect, wherein the amount of the adhesive applied in the adjacent area is greater than the amount of the adhesive applied in the side seal portion.

(Effect) The second aspect of the pants-type disposable diaper is characterized in that the amount of adhesive applied to the entire side seal is small. By applying a small amount of adhesive to the entire side seal, it is possible to prevent the adhesive force of the side seal from decreasing compared to a case where a large amount of adhesive is applied to a portion of the side seal. Furthermore, the possibility of the adhesive leaking from the side seal to the outer surface can be further reduced, and as mentioned above, the chance of the wearer feeling uncomfortable can be reduced.

<Third Aspect> The pants-type disposable diaper as described in the first aspect, wherein the amount of the adhesive applied on the inner side in the width direction of the side seal portion and in the adjacent area is greater than the amount of the adhesive applied on the outer side in the width direction of the side seal portion.

(Effect) In the manufacture of diapers, it is not easy to accurately change the amount of adhesive applied to a specific part of the diaper in such a way that the amount of adhesive applied to the adjacent area is increased and the amount of adhesive applied to the entire side seal is reduced. The reason for this is that in the manufacturing site of diapers, the strip-shaped sheet that serves as the base material of the outer body moves at high speed, so it is generally difficult to intermittently change the amount of adhesive applied to the sheet that is moving at high speed and to strictly distinguish the amount of adhesive applied with the boundary between the adjacent area and the side seal as the boundary.

Therefore, in the third aspect, the amount of adhesive applied is large not only in the adjacent area but also in the inner part of the side seal in the width direction. The inner part of the side seal in the width direction has a certain degree of distance in the width direction, so it is easier to control the application location than in the case where the amount of adhesive applied is divided by the boundary between the side seal and the adjacent area. In addition, the amount of adhesive applied on the outer side of the side seal in the width direction is kept small, so it is also possible to prevent the adhesive from leaking from the outer end of the side seal in the width direction.

<Fourth Aspect> A pants-type disposable diaper as described in any one of the first to third aspects, wherein the aforementioned elastic bending member is not provided on the outer side in the width direction of the aforementioned side seal portion.

(Effect) The fourth aspect of the pants-type disposable diaper is characterized in that there is no bending elastic member on the outer side of the side seal in the width direction. If there is a bending elastic member on the outer side of the side seal in the width direction, the outer side of the side seal in the width direction will be uneven due to the bending elastic member, and a gap will be generated between the outer periphery of the bending elastic member and the outer body in the uneven portion, so the adhesive can easily seep out from the end of the side seal in the width direction through the gap. In this aspect, in order to prevent such adhesive seepage, the bending elastic member is removed on the outer side of the side seal in the width direction.

[Effect of the invention] As described above, according to the present invention, it is possible to provide a pants-type disposable diaper that suppresses the retraction of the end of the elastic stretch member and prevents the reduction of the adhesive force of the side seal.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In addition, "elongation" refers to the value when the natural length is set to 100%. Figures 1 to 6 show a trouser-type disposable diaper 1 of an embodiment. This trouser-type disposable diaper 1 (hereinafter also referred to as a diaper) has an outer body 20 constituting a front body F and a back body B, and an inner body 10 fixed to the inner surface of the outer body 20 and integrated, and the inner body 10 is constituted by an absorbent body 13 between a liquid-permeable surface sheet 11 and a liquid-impermeable back side sheet 12. During manufacturing, after the back side of the inner body 10 is fixed to the inner surface (top side) of the outer body 20 by means of hot melt adhesive G or other bonding means, the inner body 10 and the outer body 20 are folded at the boundary between the front body F and the back body B, that is, in the center of the longitudinal direction (front-back direction), and the two side portions of the front body F and the back body B are bonded together by ultrasonic bonding or the like (it can also be heat welding or hot melt adhesive) to form a side sealing portion 21, thereby forming a waist opening and a pair of left and right leg openings to form a pants-type disposable diaper.

(Example of the structure of the outer body) As shown in Figs. 3 to 5, the outer body 20 is a nonwoven fabric sheet having a two-layer structure consisting of an upper nonwoven fabric 20A and a lower nonwoven fabric 20B (that is, the lower nonwoven fabric in this form becomes the outermost nonwoven fabric), and various elastic members are arranged between the upper nonwoven fabric 20A and the lower nonwoven fabric 20B, and between the nonwoven fabrics of the folded portion 20C formed by folding the lower nonwoven fabric 20B toward the inner surface at the edge of the waist opening to impart stretchability. The flat shape has a concave leg line formed in the middle of each of the two side parts, and the leg line is used to form a leg opening, thereby forming an overall shape similar to an hourglass.

In particular, in the illustrated outer body 20, in the unfolded shape shown in Figures 1 and 2, as an elastic member, there is a waist elastic member 24, which is arranged near the waist opening 23; a plurality of waist elastic members 25, which are spaced apart in the longitudinal direction and arranged along the width direction in the front body F and the back body B, and in the front body F and the back body B, respectively, there are a plurality of curved elastic members 26, 28 different from the waist elastic member 25, which are curved into a pattern from the side sealing portion 21 on one side along the leg opening on one side toward the crotch, across the crotch and along the leg opening on the other side to the side sealing portion 21 on the other side, without crossing each other and arranged at intervals. These elastic members 24 to 26, 28 are fixed in an extended state at a predetermined extension rate along their respective extension directions. In addition, in the outer body 20, there is no so-called leg elastic member, which is continuous from the side seal of the front body F to the side seal of the back body B along the leg line 29.

The waist elastic member 24 is a plurality of thin elastic members such as rubber threads arranged at intervals in the vertical direction near the edge of the waist opening within the range of the side sealing portion 21 where the front body F and the back body B are joined together, and the diaper is worn on the body by giving stretching force in a manner that tightens around the waist of the body. The waist elastic member 24 uses rubber threads in the example shown, but a belt-shaped stretchable member, for example, may also be used. In addition, the waist elastic member 24 in the illustrated form is sandwiched between the non-woven fabric of the folded portion 20C of the lower non-woven fabric 20B in the waist, but it may also be sandwiched between the upper non-woven fabric 20A and the lower non-woven fabric 20B.

The waist elastic member 25 is a thin elastic member such as rubber thread which is arranged at intervals in the vertical direction and is spread over the range from the upper part to the lower part of the side seal portion, and applies stretching force in the width direction to the waist parts of the front body F and the back body B respectively, so that the diaper fits closely to the body. In addition, the boundary between the waist elastic member 24 and the waist elastic member 25 does not need to be clear. For example, even if the number of elastic members arranged at intervals in the vertical direction in the front body F and the back body B in the width direction is not specified, as long as a few elastic members on the upper side function as waist elastic members, the remaining elastic members function as waist elastic members.

In the back body B, the back bending elastic member 26 arranged separately from the waist elastic member 25 is a thin and long elastic member such as a rubber thread. The back bending elastic member 26 can be one, preferably a plurality of, and in the example shown, there are three rubber thread-like elastic members. These back bending elastic members 26 do not cross each other but are arranged at intervals. This back bending elastic member 26 is not arranged as a bundle of two or three elastic stretch members at a relatively close interval, but is arranged at intervals of 3 to 20 mm, preferably at intervals of 6 to 16 mm, so as to form a predetermined stretch area.

In the front body F of the outer body 20, the abdominal bending elastic member 28, which is separately arranged from the waist elastic member 25, is a thin and long elastic member such as a rubber thread. The abdominal bending elastic member 28 can be one, preferably a plurality of, and in the example shown in the figure, there are three thread-like elastic members, and these abdominal bending elastic members 28 do not cross each other, but are arranged at intervals. This abdominal bending elastic member 28 is not actually arranged as a bundle of two or three elastic stretch members at a relatively close interval, but is arranged at intervals of 3 to 20 mm in a manner to form a prescribed stretch area, preferably at least three at intervals of 6 to 16 mm.

In addition, in the example shown in the figure, the waist elastic member 25 and the bending elastic members 26 and 28 arranged in the front body F and the back body B are continuously fixed to the outer body during manufacturing, as shown in Figures 7 and 8, and then a part or all of the overlapping part with the inner body is finely cut with a prescribed cutting pattern CP to become a non-contractile part where the contraction force does not act (that is, the overlapping part with the cutting pattern CP of Figures 7 and 8), and the part that is bent and extended laterally than this non-contractile part becomes the contraction part where the contraction force acts (that is, the remaining continuous part of the waist elastic member 25 and the bending elastic members 26 and 28 that is more laterally than the cutting pattern CP of Figures 7 and 8). Therefore, the waist elastic member 25 and the bending elastic members 26 and 28 are arranged to cross the inner body 10 from the side sealing portion 21 on one side and continue to the side sealing portion 21 on the other (opposite) side, and then part or all of the overlapping portion with the inner body is finely cut off. In this way, the inner body (especially the absorbent body 13) can be further prevented from curling in the width direction. Of course, the waist elastic member 25 and the bending elastic members 26 and 28 can also be arranged to cross the inner body 10 and continue.

The outer body 20 can be manufactured by the techniques described in, for example, Japanese Patent Publication No. 4-28363 and Japanese Patent Publication No. 11-332913. In addition, the inner body 10 can be cut and discontinuous by cutting the bending elastic members 26 and 28, and the cutting methods described in Japanese Patent Publication No. 2002-35029, Japanese Patent Publication No. 2002-178428 and Japanese Patent Publication No. 2002-273808 can be appropriately adopted.

Unlike the example shown in the figure, the curved elastic member may be provided only on one side of the front body F and the back body B. Furthermore, when the curved elastic members 26 and 28 are arranged on both sides of the front body F and the back body B, a part or all of the group of the curved elastic members arranged on the side of the front body F and a part or all of the group of the curved elastic members arranged on the side of the back body B may be crossed (not shown), but it is suitable that the group of the curved elastic members 28 arranged on the side of the front body F and the group of the curved elastic members 26 arranged on the side of the back body B shown in the example shown in the figure do not cross each other, and are slightly offset in the middle part in the front-back direction, especially in the front body F, so as to be separated from each other in the longitudinal direction.

Furthermore, the curved elastic members 26 and 28 may not be curved as a whole, but may have a straight line portion in part.

The elongation of the elastic members 24 to 26 and 28 when fixed can be appropriately specified. In the case of a normal infant diaper, the waist elastic member 24 can be set to about 230 to 320%, the waist elastic member 25 can be set to about 230 to 320%, and the bending elastic members 26 and 28 can be set to about 160 to 300%.

(Fixing of elastic components by hot melt adhesive)

The elastic waist member 24, the elastic waist member 25, and the bending elastic members 26 and 28 are sandwiched between a pair of sheets 20A and 20B constituting the outer body 20, and are bonded and fixed to these sheets 20A and 20B by a hot melt adhesive, and the amount of the hot melt adhesive applied greatly affects the flexibility of the outer body 20. Therefore, as shown in FIG. 7, the application area B1 for fixing the elastic waist member 24 and the elastic waist member 25 is preferably provided only at the configuration part and its vicinity of the elastic waist member 24, and the configuration part and its vicinity of the elastic waist member 25.

FIG7 shows the hot melt adhesive application area B1 in the manufacturing step, and the hot melt adhesive used to fix the waist elastic member 24 and the waist elastic member 25 to the two layers 20A and 20B is actually applied to the configuration part of each elastic member 24 and 25 and its vicinity. The application of this adhesive can be achieved by using the two layers 20A and 20B to clamp the elastic members 24 and 25 with the adhesive applied on the outer peripheral surface. The application of the adhesive to the outer peripheral surface of the elastic members 24 and 25 can be achieved by, for example, a rubber band nozzle of Nordson.

FIG8 shows the application area B2 of the hot melt adhesive in the manufacturing process, and shows the state before the portion of the elastic members 26 and 28 crossing the inner body 10 shown by the two-point chain line is cut. In addition, in FIG8, the waist elastic member 24 and the waist elastic member 25 are conveniently omitted for easy reading. As shown in FIG8, the hot melt adhesive is also applied to almost the entire surface of the disposable diaper (the position of the application area B2). This is used for bonding between the upper non-woven fabric 20A and the lower non-woven fabric 20B, and for bonding the waist elastic member 25 and the bending elastic members 26 and 28. In addition, in the manufacture of diapers, the upper non-woven fabric 20A and the lower non-woven fabric 20B in the initial step are cloth-like sheets, and the inner part of the leg line 29 (the part where the wearer's legs are inserted) also has non-woven fabric, so adhesive is also applied to this part, but this part will be cut off in the subsequent steps. In addition, the adhesive shown in Figure 8 is generally applied to either the upper non-woven fabric 20A or the lower non-woven fabric 20B.

In the above, as shown in Figures 7 and 8, it has been described that the adhesive is applied to both the application areas B1 and B2 to manufacture the diaper. The feature of the present invention is that, as shown in Figure 10 (A), in the application of the adhesive, the amount of adhesive applied in the adjacent area N1 adjacent to the inner side in the width direction of the side seal 21 is greater than the amount of adhesive applied in the area N2 on the outer side in the width direction of the side seal 21.

FIG9 shows that an adhesive different from the adhesive applied in FIG7 and FIG8 is applied to the adjacent area N1 adjacent to the inner side of the side seal 21 in the width direction. The portion where the adhesive is applied is shown as the application portion B3. By applying this different adhesive, the amount of adhesive applied in the adjacent area N1 can be increased. As a result, the amount of adhesive applied in the adjacent area N1 is increased compared to the area where the adhesive is not applied (particularly the area N2 on the outer side of the side seal 21 in the width direction). In addition, the amount of adhesive applied in the adjacent area N1 is increased, thereby firmly bonding the ends of the bending elastic members 26 and 28 to the upper non-woven fabric 20A and the lower non-woven fabric 20B, thereby suppressing the retraction of the ends of the bending elastic members 26 and 28. In FIG. 10 and FIG. 11, the result of firmly bonding the ends of the bending elastic member 28 shows that the retracted portion 28A of the abdominal bending elastic member 28 is small. Furthermore, the amount of adhesive applied in the area N2 outside the width direction of the side seal 21 is small, thereby preventing the adhesive from leaking outward from the end portion outside the width direction of the side seal 21. As mentioned above, if the amount of adhesive applied in the side seal 21 increases, there is a problem of reduced bonding strength of the side seal 21, so by reducing the amount of adhesive applied in the area N2 outside the width direction of the side seal 21, the bonding strength of the side seal 21 is prevented from being reduced.

FIG. 10(A) shows that a portion B4 with a small amount of adhesive applied is formed only in the area N2 on the outside in the width direction of the side seal 21. However, it is more preferable that a portion B4 with a small amount of adhesive applied is also formed in the area on the inside in the width direction of the side seal 21 as shown in FIG. 10(B). As the amount of adhesive applied in the side seal 21 decreases, the bonding strength of the side seal 21 can be prevented from decreasing. Furthermore, as the amount of adhesive applied in the side seal 21 decreases, the adhesive can be prevented from leaking out to the outer surface of the side seal 21 and hardening, and the wearer can be prevented from touching the hardened portion and feeling uncomfortable.

FIG11 shows another embodiment. FIG11(A) shows a configuration in which a portion B3 where a large amount of adhesive is applied is formed not only in the adjacent area N1 but also on the inner side of the side seal 21 in the width direction. If the amount of adhesive applied in the side seal 21 increases, the bonding strength of the side seal 21 decreases. From this point of view, the configuration of FIG11(A) is not good. However, during the manufacturing process, the upper non-woven fabric 20A and the lower non-woven fabric 20B move at a high speed, so it is difficult to intermittently apply the adhesive only at the specified position (adjacent area N1) of the upper non-woven fabric 20A and the lower non-woven fabric 20B. Therefore, even if the coating is applied slightly outside the adjacent area N1 in the width direction, it is within the permissible range.

FIG11(B) shows that there is no area B3 with a large amount of adhesive applied in the portion (N3 portion) outside the width direction of the adjacent area N1. In this configuration, the retracted portion 28A of the ventral bending elastic member 28 does not overlap the side seal 21. If the ventral bending elastic member 28 is present in the side seal 21, unevenness will be generated due to the ventral bending elastic member 28 in the side seal 21, and a gap will be generated between the outer periphery of the ventral bending elastic member 28 and the outer body in the uneven portion, so the adhesive easily seeps out from the end portion outside the width direction of the side seal 21 through the gap. In this embodiment, the retracted portion 28A of the ventral bending elastic member 28 does not overlap with the side seal 21, so it is possible to prevent such adhesive from seeping out. In addition, in the embodiments of FIG. 10(A) and FIG. 10(B) and the embodiment of FIG. 11(A), the retracted portion 28A of the ventral bending elastic member 28 does not exist in the area N2 on the outside in the width direction of the side seal 21. This is because the amount of adhesive applied in the area N2 on the outside in the width direction of the side seal 21 is reduced. Therefore, in the area N2 on the outside in the width direction of the side sealing portion 21, the possibility of the following situation can be reduced: due to the generation of unevenness due to the ventral bending elastic member 28 in the side sealing portion 21, a gap will be generated between the outer periphery of the ventral bending elastic member 28 and the outer body in the uneven portion, so the adhesive can easily seep out from the end on the outside in the width direction of the side sealing portion 21 through the gap.

In the above description, in order to form the area B3 where the amount of adhesive applied is large, a new adhesive form different from the adhesive applied in Figures 7 and 8 is applied, but the present invention is not limited to this form. For example, as shown in Figure 8, in the application area B2, the amount of adhesive applied can be set to be larger in the portion corresponding to the adjacent area N1 than in other portions, thereby forming the area B3 where the amount of adhesive applied is large.

In the description of this embodiment, the outer side of the side seal 21 in the width direction refers to the portion located on the outer side in the width direction when the width of the side seal is roughly divided into two parts; the inner side of the side seal 21 in the width direction refers to the portion located on the inner side in the width direction when the width of the side seal is roughly divided into two parts. Furthermore, the adjacent area N1 refers to the area from the inner edge of the side seal 21 in the width direction as the starting point to the portion of 5 to 60 mm inward in the width direction.

The amount of adhesive applied to the area B3 where the amount of adhesive applied is large is about 11 to 25 g/m ² , and the amount of adhesive applied to the area B4 where the amount of adhesive applied is small is about 1 to 5 g/m ² . The amount of adhesive applied to the area B3 where the amount of adhesive applied is large is about 2 to 25 times the amount of adhesive applied to the area B4 where the amount of adhesive applied is small.

In Fig. 9, the area B3 where the adhesive is applied in a large amount is provided on both the abdominal elastic member 28 of the front body F and the dorsal elastic member 26 of the back body B, but it may be provided on only one of them. Furthermore, the area B3 where the adhesive is applied in a large amount and the area B4 where the adhesive is applied in a small amount may be provided only in the area where the abdominal elastic member 28 and the dorsal elastic member 26 exist. That is, it is not necessary to provide them at a position far away from the abdominal elastic member 28 and the dorsal elastic member 26 in the longitudinal direction. Specifically, it can also be set in the range of 0.5 to 10 mm apart in the longitudinal direction from the ventral bending elastic member 28 and the dorsal bending elastic member 26. For example, in the embodiment shown in Figure 10 (A), three ventral bending elastic members 28 can be separated and arranged approximately in parallel at a predetermined distance in the longitudinal direction. At this time, the upper end of the area B3 where the amount of adhesive applied is large can be set as the upper end of the area B3 where the upper end portion of the abdominal bending elastic member 28T located closest to the abdomen (corresponding to the outer side portion of the abdominal bending elastic member 28 in FIG. 10(A)) separated 0.5 to 10 mm upward (abdomen) (i.e., T1 becomes 0.5 to 10 mm). Similarly, the position 0.5 to 10 mm away from the upper end of the abdominal-side bending elastic member 28U located closest to the hips (corresponding to the outer side portion of the abdominal-side bending elastic member 28 in FIG. 10 (A)) downward (hips) (that is, U1 becomes 0.5 to 10 mm) may be set as the lower end of the portion B3 where the amount of adhesive applied is large. In addition, from the viewpoint of ease of manufacturing, it is preferred that the entire portion between the abdominal-side bending elastic member 28T closest to the hips and the abdominal-side bending elastic member 28U closest to the hips be set as the portion B3 where the amount of adhesive applied is large. Therefore, in the case of three ventral bending elastic members 28, the length P1 in the longitudinal direction of the portion B3 where the amount of adhesive applied is large is preferably set to about 15 to 50 mm.

In the above description, the area B3 where the amount of adhesive applied is large formed around the ventral bending elastic member 28 is described, and the same value is also applied to the area B3 where the amount of adhesive applied is large formed around the dorsal bending elastic member 26. Furthermore, the longitudinal range of the area B4 where the amount of adhesive applied is small can be set to the same range as the area B3 where the amount of adhesive applied is large.

Furthermore, when forming a portion B3 where a large amount of adhesive is applied, in the case where a reinforcing adhesive different from the adhesive applied throughout the entire surface as shown in FIG. 8 is to be applied (a reinforcing adhesive for preventing the ends of the bending elastic members 26 and 28 from retracting), the reinforcing adhesive may be applied on a sheet (e.g., an upper non-woven fabric 20A) on the opposite side of a sheet (e.g., a lower non-woven fabric 20B) on which the adhesive is applied throughout the entire surface. In addition, the adhesive applied to the entire surface is an adhesive that serves as a base material for bonding the upper non-woven fabric 20A and the lower non-woven fabric 20B and the flexible elastic members 26 and 28 disposed therebetween; the reinforcing adhesive is an adhesive used to prevent the ends of the flexible elastic members 26 and 28 from retracting. The adhesive applied to the entire surface and the reinforcing adhesive may be of different types or of the same type. The adhesive applied to the entire surface and the reinforcing adhesive are not particularly limited, and for example, a hot melt adhesive may be used. The hot melt adhesive is not particularly limited, and for example, EVA (ethylene-vinyl acetate copolymer)-based adhesives, adhesive rubber-based adhesives (elastic-based adhesives), olefin-based adhesives, polyester-polyamide-based adhesives, and the like can be used.

(Example of the structure of the inner body) As shown in Figs. 4 to 6, the inner body 10 has a structure in which an absorbent body 13 is present between a liquid-permeable surface sheet made of a nonwoven fabric or the like and a liquid-impermeable back side sheet 12 made of polyethylene or the like, so as to absorb and retain the excrement that has passed through the liquid-permeable surface sheet 11.

As the liquid-permeable surface sheet 11 covering the surface side (skin contact side) of the absorbent body 13, a non-woven fabric with or without holes, a porous plastic sheet, etc. can be appropriately used. The raw material fibers constituting the non-woven fabric include olefins such as polyethylene and polypropylene, synthetic fibers such as polyesters and polyamides, regenerated fibers such as rayon and copper ammonium fibers, natural fibers such as cotton, etc.; non-woven fabrics obtained by appropriate processing methods such as hydroentanglement, spunbonding, thermal bonding, melt-blowing, and needle punching can be used. Among these processing methods, the hydroentanglement method excels in softness and drape, and the thermal bonding method excels in fluffiness and softness. When a plurality of through holes are formed in the liquid-permeable surface sheet 11, urine etc. can be quickly absorbed and a sheet with excellent dryness can be obtained. The liquid-permeable surface sheet 11 is rolled up at the side edge of the absorbent body 13 and extends to the back side of the absorbent body 13.

The liquid-impermeable back side sheet 12 covering the back side (non-skin contact side) of the absorbent body 13 is made of a liquid-impermeable plastic sheet such as polyethylene or polypropylene, but in recent years, a moisture-permeable sheet is appropriately used from the perspective of preventing dampness. This water-blocking and moisture-permeable sheet is, for example, a microporous sheet obtained by melting and mixing an inorganic filler in an olefin resin such as polyethylene or polypropylene to form a sheet, and then extending it along one or two axes.

As the absorbent 13, a known absorbent is used, for example, a multitude of filaments of pulp fiber, cellulose acetate, etc., or a non-woven fabric as a base material, and a superabsorbent polymer is mixed and bonded as needed. The absorbent in the illustrated example is formed into a roughly square shape in plane, and its width is set to a size that does not make the wearer feel hard due to contact with the crotch. This absorbent 13 can be packaged with a packaging sheet 14 having liquid permeability and liquid retention properties such as wrinkled paper as needed to maintain the shape and polymer. The shape of the absorber 13 may be, in addition to the rectangular shape shown in the figure, an hourglass shape (a narrowed shape) in which the width of the crotch portion is narrower than the back side and the abdomen side.

Preferably, three-dimensional pleats BS that fit the leg circumference are formed on both sides of the inner body 10. The three-dimensional pleats BS are formed by a pleated nonwoven fabric 15. As the pleated nonwoven fabric, a nonwoven fabric that is folded back to form a two-layer sheet as shown in Figures 5 and 6 is appropriately used. It is rolled into the side edge of the absorbent body 13 from the upper side of the absorbent body 13 together with the liquid-permeable surface sheet 11 and extends to and is bonded to the back side of the absorbent body 13. More specifically, the pleated non-woven fabric 15 is bonded in the middle portion in the long side direction of the diaper 1 by means of a hot melt adhesive or the like in a range from the middle portion in the width direction to the back side of the absorbent body 13, leaving three-dimensional pleats BS; and in the front and rear end portions in the long side direction, it is bonded in a range from the middle portion in the width direction to the end edge of one side in a range to the back side of the absorbent body 13, and the portion forming the three-dimensional pleats BS is folded and bonded to the top portion of the absorbent body 13 by means of a hot melt adhesive or the like.

Inside the pleated nonwoven fabric 15 formed by the two-layer nonwoven fabric, a plurality of thread-like elastic stretch members 16 are arranged on the side of the raised front end. In the product state, the thread-like elastic stretch member 16 makes the part of the nonwoven fabric protruding more than the side edge of the absorbent body stand up by its elastic stretch force to form a three-dimensional pleat BS as shown by the two-dot chain line in Figure 4.

The liquid-impermeable back side sheet 12 is inserted into the two-layer sheet-shaped pleated nonwoven fabric 15 and forms a leak-proof wall at the lower end side of the three-dimensional pleats BS as shown in FIG4. As the liquid-impermeable back side sheet 12, it is desirable to use an opaque sheet material in a manner that does not show the brown color of defecation and urine. As opacification, a sheet material obtained by adding a pigment or filler such as calcium carbonate, titanium oxide, zinc oxide, white carbon, clay, talc, barium sulfate, etc. to plastic and forming it into a film is appropriately used.

As the thread-like elastic expansion member 16, the commonly used raw materials such as styrene rubber, olefin rubber, urethane rubber, ester rubber, polyurethane, polyethylene, polystyrene, styrene butadiene polymer, silicone, polyester, etc. can be used. In order to make it difficult to be seen from the outside, it is suitable to be arranged to have a thickness of 925 dtex or less, a tension of 150 to 350%, and a spacing of 7.0 mm or less. In addition, instead of the thread-like elastic expansion member, a belt-like elastic expansion member with a certain degree of width can also be used.

The raw material fibers constituting the aforementioned pleated nonwoven fabric 15 are the same as those of the liquid-permeable surface sheet 11. In addition to being set as synthetic fibers such as olefins such as polyethylene or polypropylene, polyesters, and polyamides, it can also be set as regenerated fibers such as rayon or copper ammonium fibers, and natural fibers such as cotton. It is possible to use nonwoven fabrics obtained by appropriate processing methods such as spunbonding, thermal bonding, meltblowing, and needle punching. However, in order to prevent moisture, in particular, nonwoven fabrics with excellent air permeability that suppress the mass per unit area can also be used. Furthermore, in order to prevent the penetration of urine, etc., prevent skin inflammation and improve the touch of the skin (dry feeling), it is expected to use a water-repellent non-woven fabric coated with a silicone-based, wax-metal-based, alkyl chromium chloride-based water-repellent, etc. as the wrinkled non-woven fabric 15.

(Front and rear push-down plates) As also shown in Fig. 1 and Fig. 4, front and rear push-down plates 50 and 60 are provided to cover the front and rear ends of the inner body 10 mounted on the inner surface of the outer body 20 and prevent leakage from the front and rear edges of the inner body 10. To explain the illustrated form in more detail, the front push-down plate 50 extends from the inner surface of the folded portion 20C of the waist side end portion of the inner surface of the front body F throughout the width direction to a position overlapping with the front end portion of the inner body 10; the rear push-down plate 60 extends from the inner surface of the folded portion 20C of the waist side end portion of the inner surface of the back body B throughout the width direction to a position overlapping with the rear end portion of the inner body 10. If a small non-adhesive portion is provided along the entire width (or only in the center) at the crotch edges of the front and rear pressing sheets 50, 60, the adhesive will not be exposed, and this portion will slightly float from the surface sheet and can function as a leak-proof wall.

As shown in the figure, if the front and rear pressing pieces 50 and 60 are installed as individual units, there is an advantage that the degree of freedom in selecting raw materials becomes higher, but there is a disadvantage that the materials and manufacturing steps increase. Therefore, the folded portion 20C formed by folding back the outer body 20 toward the inner surface of the diaper 1 can be extended to the portion overlapping with the absorbent body 13 to form a portion equivalent to the above-mentioned pressing pieces 50 and 60.

[Industrial Applicability] The present invention can be used in pants-type disposable diapers such as the above-mentioned example.

1: Pants-type disposable diaper (diaper) 10: Inner body 11: Liquid-permeable surface sheet 12: Liquid-impermeable back side sheet 13: Absorbent body 14: Packaging sheet 15: Pleated nonwoven fabric 16: Silky elastic stretch member 20: Outer body 20A: Upper nonwoven fabric (sheet layer) 20B: Lower nonwoven fabric (sheet layer) 20C: Folded part 21: Side seal 23: Near waist opening 24: Elastic waist member (elastic member) 25: Elastic waist member (elastic member) 26: Back curved elastic member (curved elastic member, elastic member) 28: Abdominal curved elastic member (curved elastic member, elastic member) 28A: Abdomen The retracted part of the side bending elastic member 28T: The abdominal bending elastic member closest to the abdomen 28U: The abdominal bending elastic member closest to the hips 29: Leg circumference 50: Front push-press plate (push-press plate) 60: Back push-press plate (push-press plate) BS: Three-dimensional pleats F: Front body B: Back body B1, B2: Coating area B3: Area with more coating P1: Length of the area with more coating in the longitudinal direction B4: Area with less coating CP: Cutting pattern G: Hot melt adhesive M: Part N1: Adjacent area on the inner side of the width direction of the side seal N2: Area on the outer side of the width direction of the side seal N3: Part of the outer side of the width direction of the adjacent area

Fig. 1 is a plan view (inner surface side) of a pants-type disposable diaper in an unfolded state. Fig. 2 is a plan view (outer surface side) of a pants-type disposable diaper in an unfolded state. Fig. 3 is a cross-sectional view along the C-C line in Fig. 1. Fig. 4 is a cross-sectional view along the A-A line in Fig. 1. Fig. 5 is a cross-sectional view along the B-B line in Fig. 1. Fig. 6 is a perspective view of a pants-type disposable diaper in a worn state. Fig. 7 is a plan view showing an example of a coating pattern of an adhesive for bonding a waist elastic member and a waist elastic member. Fig. 8 is a plan view showing a coating pattern of an adhesive for bonding a bending elastic member and a waist elastic member. FIG. 9 is a plan view showing a portion where a relatively large amount of adhesive is applied to bond a flexible elastic member; wherein the representation of an area where the amount of adhesive applied is reduced is omitted. FIG. 10 is an enlarged view of the M portion of FIG. 9 ; FIG. 10(A) and FIG. 10(B) are different implementation forms, and the areas where the amount of adhesive applied is reduced are different. FIG. 11 is a variation of FIG. 10 ; FIG. 11(A) and FIG. 11(B) are different implementation forms, and the areas where the amount of adhesive applied is increased are different.

Domestic storage information (please note the storage institution, date, and number in order) None

Overseas storage information (please note the storage country, institution, date, and number in order) None

10: Interior body

20:External body

21: Side seal

26: Dorsal bending elastic member (bending elastic member, elastic member)

28: Ventral bending elastic member (bending elastic member, elastic member)

29: Leg circumference

F: Predecessor

B: Back

B2: Application area

B3: Areas with large amounts of application

CP: Cutting pattern

M: Part

Claims (4)

A trouser-type disposable diaper, which has an outer shell forming a front body and a back body, and the two side parts of the outer shell in the front body and the two side parts of the outer shell in the back body are respectively joined to form side seals, thereby forming a waist opening and a pair of left and right leg openings; the trouser-type disposable diaper is characterized in that: a bending elastic member of the side seal part that is bent and extended from one side to the other side is bonded to at least one of the front body and the back body in the outer shell by an adhesive; the amount of the adhesive applied in the adjacent area adjacent to the inner side of the width direction of the side seal part is greater than that in the adjacent area adjacent to the side seal part. The amount of the adhesive applied on the outer side of the seal in the width direction is greater; the two ends of the aforementioned flexible member are respectively located at the outer ends of the width direction of the aforementioned side seal or the aforementioned adjacent area; the outer side of the width direction of the aforementioned side seal refers to the portion located on the outer side of the width direction when the width of the aforementioned side seal is roughly divided into two parts; the inner side of the width direction of the aforementioned side seal refers to the portion located on the inner side of the width direction when the width of the aforementioned side seal is roughly divided into two parts; the aforementioned adjacent area refers to the area from the inner edge of the width direction of the aforementioned side seal as the starting point to the portion separated by 5 to 60 mm inward in the width direction. The pants-type disposable diaper as described in claim 1, wherein the amount of the adhesive applied in the adjacent area is greater than the amount of the adhesive applied in the side seal. The pants-type disposable diaper as described in claim 1, wherein the amount of the adhesive applied on the inner side in the width direction of the side seal and in the adjacent area is greater than the amount of the adhesive applied on the outer side in the width direction of the side seal. A pants-type disposable diaper as described in any one of claims 1 to 3, wherein the aforementioned bending elastic member is not provided on the outer side in the width direction of the aforementioned side seal.